08/18/2026
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A satellite-tracked female snowy owl in the eastern Canadian Arctic spent 186 days on sea ice, hunting ducks at open water cracks in the pack ice hundreds of miles from land in total winter darkness. The biologists who tagged her expected her to fly south for the winter. She flew north onto the frozen ocean. The finding flabbergasted them. Inuit seal hunters had known about it for centuries.
Jean-François Therrien, a doctoral student at Université Laval working with professor Gilles Gauthier, tagged 12 adult female snowy owls on Bylot Island in Nunavut as part of an International Polar Year research project studying key indicator species of northern ecosystems. When winter came, the tracking data showed something nobody in the academic world had documented with technology. Eight of the 12 owls spent more than 95 percent of their winter locations over sea ice or along the coast. Six adult females spent most of the winter far out on the Arctic sea ice. One stayed there for 186 consecutive days. She was not lost. She was not drifting. She was hunting.
The ocean freezes across the Canadian Arctic every winter but it does not freeze solid. Leads and polynyas, cracks and pools of open water, persist throughout the ice sheet. Sea ducks, particularly eiders, and seabirds concentrate at these openings because the open water is where the food is. The owls found the ducks by finding the water. Gauthier described the hypothesis directly: bird researchers at coastal field sites have observed snowy owls attacking eiders in winter. If the satellite positions of the owls matched the locations of open water leads recorded by other satellite systems, the connection would be confirmed.
The owls were not behaving like the animal most people picture when they hear the words snowy owl. Most people imagine a white bird sitting on a fence post in a farm field somewhere in Minnesota or upstate New York, hunting mice in the snow. That version of the snowy owl is real. It is the owl that shows up on Christmas Bird Counts and birding websites and nature documentaries filmed in places where camera crews can reach. The other version, the one the Inuit have always known, is an owl that flies north when winter starts, lands on sea ice in the Arctic dark, finds a crack in the frozen ocean, and sits beside it killing ducks at temperatures that drop below minus 50 degrees Fahrenheit.
The isotope data confirmed the diet shift. Stable isotope analysis of feathers showed that marine prey made up a substantial portion of the winter diet for owls that chose the sea ice. A snowy owl that breeds on lemmings in the summer and switches to sea ducks in the winter is not a rodent specialist. It is a predator that changes its entire hunting strategy, its prey base, and its habitat seasonally, moving from tundra grassland to frozen ocean the way a seasonal worker changes job sites.
Project SNOWstorm, a US-based tracking initiative that has followed more than 115 snowy owls with GPS transmitters since 2013, found the same behavior at a smaller scale on the Great Lakes. Snowy owls wintering in the northern United States moved out onto frozen Lake Michigan and Lake Erie for weeks at a time, hunting ducks at the cracks that opened and closed between wind-driven ice sheets. The researchers described the Great Lakes behavior as practice for the full Arctic version: owls learning or maintaining the ice-hunting skills that adult females use on the Arctic Ocean in the years when they stay north.
Source: Therrien et al., Université Laval / Gauthier, Université Laval / ScienceDaily / Project SNOWstorm / Birds of the World, Cornell / Old Farmer's Almanac / COSEWIC (2025).
